Benign struma ovarii-a rare monodermal ovarian teratoma-a case report

Abstract

Struma ovarii is a rare ovarian tumour, first described in 1889 by Boettlin. It is defined by the presence of thyroid tissue comprising of >50% of overall mass. It comprises 1% of all ovarian tumours and 2-5% of all ovarian teratomas. Preoperative diagnosis of struma ovarii is difficult because symptoms, clinical presentation and ultrasound are often similar to that of ovarian carcinoma. Hence most of the patients are diagnosed post operatively. Most cases of strum aovarii are benign and can be treated by excision of the ovary or by unilateral salpingo-oophorectomy. In a small number of cases, there are complications, the most important being the development of malignancy or ascites associated with pleural effusion producing a pseudo-Meigs' syndrome. This is a case of struma ovary presented with features of pseudo-Meig’s syndrome. A 68 year old post-menopausal woman presented with acute abdomen and respiratory distress with an ultrasound diagnosis of ovarian torsion, ascites and pleural effusion and found to have atrial thrombus on evaluation. She had undergone staging laparotomy, TAH+ BSO, omental biopsy and peritoneal fluid cytology. Histopathology revealed predominantly benign and mature colloid filled thyroid follicles of varying sizes lined by cuboidal epithelium surrounded by lymphocytic infiltrate and congested blood vessels, which was suggestive of struma ovary.